RC Calculations Logo Lipo Wiring

This page contains several sections pertaining to Lithium Polymer batteries.




This is a block diagram to show how Lipo battery cells are wired. It should help explain what is meant by the "s" and "p" terms. Below the diagram is a section that will show the total ratings of the pack as you change the settings.



 
Series
Connections


Building List...
 
Parallel
Connections


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Show Balancer
wire hookup? (?)

No
Yes
 

Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring
If each individual cell is rated for 3.7v @ 3000mAh and 20C discharge rate, the configuration above would result in a pack rated for 3.7v @ 3000mAh with a max discharge rate of 60 amps.





Similar to above, but this is a diagram to show how your typical prismatic Lipo battery cells are actually wired in a pack. Below the diagram is a section that will show the total ratings of the pack as you change the settings.



 
Series
Connections


Building List...
 
Parallel
Connections


Building List...
 
Show Balancer
wire hookup? (?)

No
Yes
 

Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring Lipo Internal Wiring
If each individual cell is rated for 3.7v @ 3000mAh and 20C discharge rate, the configuration above would result in a pack rated for 22.2v @ 3000mAh with a max discharge rate of 60 amps.





The diagram below shows how to wire two or more packs together.

 
Battery Pack Wiring

Use one battery pack
Use 2 series-connected battery packs (?)
Use 3 series-connected battery packs (?)
Use 2 parallel-connected battery packs (?)
 

Battery Wiring





This section explains how to measure individual cells in a Lipo pack using the balance connector. You might want to do this to verify a balancer reading, check for a dead cell, check for loose/broken/dirty connection, etc.

Note: The picture below is out of scale for illustrative purposes.

Be careful when inserting leads into the balance connector! If you accidentally short the probes against each other, you can burn up that balance wire and/or connection.

Select from the drop-down list to show how to measure each cell.

 
Building List...
 

Lipo Balancer Wiring


Notes:






The diagram below shows how to create balancer Y adaptors to balance and/or charge two batteries at the same time using one balancer unit.

Note: Thick wires in the diagram below denote the main high-current wires, while the thinner wires denote smaller wire gauges suitable for no more than 2 amps (18-20GA).

  Balance Connector

Building List...
 

Lipo Balancer Wiring


Notes:

When charging below 1.5A (1500mA), it is OK to charge through just the balancer leads, indicated by the "Low Amp" options in the diagram above.

When charging over 1.5A, it is recommended to charge through the main battery leads, and use the balance connector just for balancing. This configuration is indicated by the "High Amp" options in the diagram above. This is because the balancer leads and associated wires are too small to handle higher charge currents and may cause erroneous balancer operation due to potential voltage drop.

You may notice that when any of the "High Amp" options is selected, one of the balancer wires is unused. This is intentional as a safety precaution! If all balancer wires were used in conjunction with the main leads, and the balancer connectors were inadverdently swapped, damage will result in the balancer wire, connector, battery, or any combination of these! I usually zip-tie each balancer wire to the accociated charging lead for added safety.

Below is a picture of a completed 2s + 2s balancer/charging Y adaptor created with the "High Amp" option. The wire length was properly sized for use with the Hyperion LBA10 balancer unit. Also, the wires were extended to allow enough wire slack for easy placement into a fire-resistant container such as the Lipo Sack, Battery Bunker, etc.

Completed Y Balance Adaptor